<?php
/**
 * @file
 * Generate search pages using Search API indexes.
 */

/**
 * Implements hook_menu().
 */
function search_api_page_menu() {
  $pre = 'admin/config/search/search_api/page';
  $items[$pre] = array(
    'title' => 'Search pages',
    'description' => 'Create and configure search pages.',
    'page callback' => 'search_api_page_admin_overview',
    'access arguments' => array('administer search_api'),
    'file' => 'search_api_page.admin.inc',
    'type' => MENU_LOCAL_TASK,
  );
  $items[$pre . '/add'] = array(
    'title' => 'Add search page',
    'description' => 'Add a new search page.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('search_api_page_admin_add'),
    'access arguments' => array('administer search_api'),
    'file' => 'search_api_page.admin.inc',
    'type' => MENU_LOCAL_ACTION,
  );
  $items[$pre . '/%search_api_page'] = array(
    'title' => 'Edit search page',
    'description' => 'Configure or delete a search page.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('search_api_page_admin_edit', 5),
    'access arguments' => array('administer search_api'),
    'file' => 'search_api_page.admin.inc',
  );

  // During uninstallation, this would lead to a fatal error otherwise.
  if (module_exists('search_api_page')) {
    foreach (search_api_page_load_multiple(FALSE, array('enabled' => TRUE)) as $page) {
      $items[$page->path] = array(
        'title' => $page->name,
        'description' => $page->description ? $page->description : '',
        'page callback' => 'search_api_page_view',
        'page arguments' => array((string) $page->machine_name),
        'access arguments' => array('access search_api_page'),
        'file' => 'search_api_page.pages.inc',
        'type' => MENU_SUGGESTED_ITEM,
      );
    }
  }

  return $items;
}

/**
 * Implements hook_theme().
 */
function search_api_page_theme() {
  $themes['search_api_page_results'] = array(
    'variables' => array(
      'index' => NULL,
      'results' => array('result count' => 0),
      'items' => array(),
      'view_mode' => 'search_api_page_result',
      'keys' => '',
    ),
    'file' => 'search_api_page.pages.inc',
  );
  $themes['search_api_page_result'] = array(
    'variables' => array(
      'index' => NULL,
      'result' => NULL,
      'item' => NULL,
      'keys' => '',
    ),
    'file' => 'search_api_page.pages.inc',
  );

  return $themes;
}

/**
 * Implements hook_permission().
 */
function search_api_page_permission() {
  return array(
    'access search_api_page' => array(
      'title' => t('Access search pages'),
      'description' => t('Execute searches using the Search pages module.'),
    ),
  );
}

/**
 * Implements hook_block_info().
 */
function search_api_page_block_info() {
  $blocks = array();
  foreach (search_api_page_load_multiple(FALSE, array('enabled' => TRUE)) as $page) {
    $blocks[$page->machine_name] = array(
      'info' => t('Search block: !name', array('!name' => $page->name)),
      'cache' => DRUPAL_CACHE_PER_USER,
    );
  }
  return $blocks;
}

/**
 * Implements hook_block_view().
 */
function search_api_page_block_view($delta) {
  $page = search_api_page_load($delta);
  if ($page) {
    $block = array();
    $block['subject'] = t($page->name);
    $block['content'] = drupal_get_form('search_api_page_search_form_' . $page->machine_name, $page, NULL, TRUE);
    return $block;
  }
}

/**
 * Implements hook_forms().
 */
function search_api_page_forms($form_id, $args) {
  $forms = array();
  foreach (search_api_page_load_multiple(FALSE, array('enabled' => TRUE)) as $page) {
    $forms['search_api_page_search_form_' . $page->machine_name] = array(
      'callback' => 'search_api_page_search_form',
      'callback arguments' => array(),
    );
  }
  return $forms;
}

/**
 * Implements hook_entity_info().
 */
function search_api_page_entity_info() {
  $info['search_api_page'] = array(
    'label' => t('Search page'),
    'controller class' => 'EntityAPIControllerExportable',
    'metadata controller class' => FALSE,
    'entity class' => 'Entity',
    'base table' => 'search_api_page',
    'uri callback' => 'search_api_page_url',
    'module' => 'search_api_page',
    'exportable' => TRUE,
    'entity keys' => array(
      'id' => 'id',
      'label' => 'name',
      'name' => 'machine_name',
    ),
  );

  return $info;
}

/**
 * Implements hook_entity_property_info().
 */
function search_api_page_entity_property_info() {
  $info['search_api_page']['properties'] = array(
    'id' => array(
      'label' => t('ID'),
      'type' => 'integer',
      'description' => t('The primary identifier for a search page.'),
      'schema field' => 'id',
      'validation callback' => 'entity_metadata_validate_integer_positive',
    ),
    'index_id' => array(
      'label' => t('Index ID'),
      'type' => 'token',
      'description' => t('The machine name of the index this search page uses.'),
      'schema field' => 'index_id',
    ),
    'index' => array(
      'label' => t('Index'),
      'type' => 'search_api_index',
      'description' => t('The index this search page uses.'),
      'getter callback' => 'search_api_page_get_index',
    ),
    'name' => array(
      'label' => t('Name'),
      'type' => 'text',
      'description' => t('The displayed name for a search page.'),
      'schema field' => 'name',
      'required' => TRUE,
    ),
    'machine_name' => array(
      'label' => t('Machine name'),
      'type' => 'token',
      'description' => t('The internally used machine name for a search page.'),
      'schema field' => 'machine_name',
      'required' => TRUE,
    ),
    'description' => array(
      'label' => t('Description'),
      'type' => 'text',
      'description' => t('The displayed description for a search page.'),
      'schema field' => 'description',
      'sanitize' => 'filter_xss',
    ),
    'enabled' => array(
      'label' => t('Enabled'),
      'type' => 'boolean',
      'description' => t('A flag indicating whether the search page is enabled.'),
      'schema field' => 'enabled',
    ),
  );

  return $info;
}

/**
 * Implements hook_search_api_index_update().
 */
function search_api_page_search_api_index_update(SearchApiIndex $index) {
  if (!$index->enabled && $index->original->enabled) {
    foreach (search_api_page_load_multiple(FALSE, array('index_id' => $index->machine_name, 'enabled' => 1)) as $page) {
      search_api_page_edit($page->id, array('enabled' => 0));
    }
  }
}

/**
 * Implements hook_search_api_index_delete().
 */
function search_api_page_search_api_index_delete(SearchApiIndex $index) {
  // Only react on real delete, not revert.
  if ($index->hasStatus(ENTITY_IN_CODE)) {
    return;
  }

  foreach (search_api_page_load_multiple(FALSE, array('index_id' => $index->machine_name)) as $page) {
    search_api_page_delete($page->id);
  }
}

/**
 * Implements hook_search_api_page_insert().
 *
 * Rebuilds the menu table if a search page is created.
 */
function search_api_page_search_api_page_insert(Entity $page) {
  menu_rebuild();
}

/**
 * Implements hook_search_api_page_update().
 *
 * Rebuilds the menu table if a search page is edited.
 */
function search_api_page_search_api_page_update(Entity $page) {
  if ($page->enabled != $page->original->enabled || $page->path != $page->original->path) {
    menu_rebuild();
  }
}

/**
 * Implements hook_search_api_page_delete().
 *
 * Rebuilds the menu table if a search page is removed.
 */
function search_api_page_search_api_page_delete(Entity $page) {
  menu_rebuild();
}

/**
 * Entity URI callback.
 */
function search_api_page_url(Entity $page) {
  return array('path' => $page->path);
}

/**
 * Entity property getter callback.
 */
function search_api_page_get_index(Entity $page) {
  return search_api_index_load($page->index_id);
}

/**
 * Loads a search page.
 *
 * @param $id
 *   The page's id or machine name.
 * @param $reset
 *   Whether to reset the internal cache.
 *
 * @return Entity
 *   A completely loaded page object, or NULL if no such page exists.
 */
function search_api_page_load($id, $reset = FALSE) {
  $ret = entity_load_multiple_by_name('search_api_page', array($id), array(), $reset);
  return $ret ? reset($ret) : FALSE;
}

/**
 * Load multiple search pages at once.
 *
 * @see entity_load()
 *
 * @param $ids
 *   An array of page IDs or machine names, or FALSE to load all pages.
 * @param $conditions
 *   An array of conditions on the {search_api_page} table in the form
 *   'field' => $value.
 * @param $reset
 *   Whether to reset the internal entity_load cache.
 *
 * @return array
 *   An array of page objects keyed by machine name.
 */
function search_api_page_load_multiple($ids = FALSE, array $conditions = array(), $reset = FALSE) {
  return entity_load_multiple_by_name('search_api_page', $ids, $conditions, $reset);
}

/**
 * Inserts a new search page into the database.
 *
 * @param array $values
 *   An array containing the values to be inserted.
 *
 * @return
 *   The newly inserted page's id, or FALSE on error.
 */
function search_api_page_insert(array $values) {
  foreach (array('name', 'machine_name', 'index_id', 'path') as $var) {
    if (!isset($values[$var])) {
      throw new SearchApiException(t('Property @field has to be set for the new search page.', array('@field' => $var)));
    }
  }
  if (empty($values['description'])) {
    $values['description'] = NULL;
  }
  if (empty($values['options'])) {
    $values['options'] = array();
  }
  $fields = array(
    'name' => $values['name'],
    'machine_name' => $values['machine_name'],
    'description' => $values['description'],
    'enabled' => empty($values['enabled']) ? 0 : 1,
    'index_id' => $values['index_id'],
    'path' => $values['path'],
    'options' => $values['options'],
  );
  if (isset($values['id'])) {
    $fields['id'] = $values['id'];
  }

  $page = entity_create('search_api_page', $fields);
  $page->save();

  return $page->id;
}

/**
 * Changes a page's settings.
 *
 * @param $id
 *   The edited page's ID.
 * @param array $fields
 *   The new field values to set.
 *
 * @return
 *   1 if fields were changed, 0 if the fields already had the desired values.
 */
function search_api_page_edit($id, array $fields) {
  $page = search_api_page_load($id, TRUE);
  $changeable = array('name' => 1, 'description' => 1, 'path' => 1, 'options' => 1, 'enabled' => 1);
  foreach ($fields as $field => $value) {
    if (isset($changeable[$field]) || $value === $page->$field) {
      $page->$field = $value;
      $new_values = TRUE;
    }
  }
  // If there are no new values, just return 0.
  if (empty($new_values)) {
    return 0;
  }

  $page->save();

  return 1;
}

/**
 * Deletes a search page.
 *
 * @param $id
 *   The ID of the search page to delete.
 *
 * @return
 *   TRUE on success, FALSE on failure.
 */
function search_api_page_delete($id) {
  $page = search_api_page_load($id, TRUE);
  if (!$page) {
    return FALSE;
  }
  $page->delete();

  menu_rebuild();

  return TRUE;
}

/**
 * Display a search form.
 *
 * @param Entity $page
 *   The search page for which this form is displayed.
 * @param $keys
 *   The search keys.
 * @param $compact
 *   Whether to display a compact form (e.g. for blocks) instead of a normal one.
 */
function search_api_page_search_form(array $form, array &$form_state, Entity $page, $keys = NULL, $compact = FALSE) {
  $form['keys_' . $page->id] = array(
    '#type' => 'textfield',
    '#title' => t('Enter your keywords'),
    '#title_display' => $compact ? 'invisible' : 'before',
    '#default_value' => $keys,
    '#size' => $compact ? 15 : 30,
  );
  $form['base_' . $page->id] = array(
    '#type' => 'value',
    '#value' => $page->path,
  );
  $form['id'] = array(
    '#type' => 'hidden',
    '#value' => $page->id,
  );
  $form['submit_' . $page->id] = array(
    '#type' => 'submit',
    '#value' => t('Search'),
  );

  if (!$compact) {
    $form = array(
      '#type' => 'fieldset',
      '#title' => check_plain($page->name),
      'form' => $form,
    );
    if ($page->description) {
      $form['text']['#markup'] = '<p>' . nl2br(check_plain($page->description)) . '</p>';
      $form['text']['#weight'] = -5;
    }
  }

  return $form;
}

/**
 * Validation callback for search_api_page_search_form().
 */
function search_api_page_search_form_validate(array $form, array &$form_state) {
  if (!trim($form_state['values']['keys_' . $form_state['values']['id']])) {
    form_set_error('keys_' . $form_state['values']['id'], t('Please enter at least one keyword.'));
  }
}

/**
 * Submit callback for search_api_page_search_form().
 */
function search_api_page_search_form_submit(array $form, array &$form_state) {
  $keys = trim($form_state['values']['keys_' . $form_state['values']['id']]);
  // @todo Take care of "/"s in the keys
  $form_state['redirect'] = $form_state['values']['base_' . $form_state['values']['id']] . '/' . $keys;
}